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911.
This paper studies an inverse problem of identifying the coefficient of parabolic equation when the final observation is given, which has important application in a large fields of applied science. Based on the optimal control framework, the existence and necessary condition of the minimum for the control functional are established. Since the optimal control problem is nonconvex, one may not expect a unique solution. However, in this paper the solution is proved to be locally unique. After the necessary condition is transformed into an elliptic bilateral variational inequality, an algorithm and some numerical experiments are proposed in the paper. The numerical results show that the algorithm designed in this paper is stable and that the coefficient is recovered very well. 相似文献
912.
We show that some cardinal arithmetic configurations related to the negation of the Shelah Weak Hypothesis and natural from
the forcing point of view are impossible.
Received: 8 September 1999 / Published online: 3 October 2001 相似文献
913.
We present a nonlinear mathematical model for numerical analysis of the behavior of concrete subject to transient heating according to the standard ISO fire curve. The mathematical model consists of the balance equations (conservations laws) with boundary and initial conditions, constitutive laws and material data for concrete at high temperatures. The numerical algorithm based on finite element method for the numerical solution of the energy equation and finite difference method for the mass balance equations is presented. Distributions of temperature, saturation of water and water vapor pressure are demonstrated. 相似文献
914.
Yukinobu Toda 《Advances in Mathematics》2008,217(6):2736-2781
For a K3 surface X and its bounded derived category of coherent sheaves D(X), we have the notion of stability conditions on D(X) in the sense of T. Bridgeland. In this paper, we show that the moduli stack of semistable objects in D(X) with a fixed numerical class and a phase is represented by an Artin stack of finite type over C. Then following D. Joyce's work, we introduce the invariants counting semistable objects in D(X), and show that the invariants are independent of a choice of a stability condition. 相似文献
915.
In this paper we will generalize the representation theory developed for finite Tarski algebras given in [7]. We will introduce
the notion of Tarski space as a generalization of the notion of dense Tarski set, and we will prove that the category of Tarski
algebras with semi-homomorphisms is dually equivalent to the category of Tarski spaces with certain closed relations, called
T-relations. By these results we will obtain that the algebraic category of Tarski algebras is dually equivalent to the category
of Tarski spaces with certain partial functions. We will apply these results to give a topological characterization of the
subalgebras.
Received August 21, 2005; accepted in final form December 5, 2006. 相似文献
916.
In this paper we establish the existence and the uniqueness of positive solutions for Dirichlet boundary value problems of nonlinear elliptic equations with singularity. We obtain the existence and the uniqueness by using the mixed monotone method in the cone theory. Moreover, we give an iterative method of constructing the solution. The rate of convergence of the iterative sequence is analyzed. 相似文献
917.
A class of differential-delay systems with hysteresis is considered. Conditions ensuring boundedness of solutions and related asymptotic and integrability properties are expressed in terms of data associated with the linear component of the overall system and a Lipschitz constant associated with the hysteretic component. 相似文献
918.
V.N. Berestovski? 《Differential Geometry and its Applications》2008,26(5):514-535
We study in this paper previously defined by V.N. Berestovskii and C.P. Plaut δ-homogeneous spaces in the case of Riemannian manifolds and prove that they constitute a new proper subclass of geodesic orbit (g.o.) spaces with non-negative sectional curvature, which properly includes the class of all normal homogeneous Riemannian spaces. 相似文献
919.
V. Yurko 《Journal of Differential Equations》2008,244(2):431-443
We study boundary value problems on compact graphs without circles (i.e. on trees) for second-order ordinary differential equations with nonlinear dependence on the spectral parameter. We establish properties of the spectral characteristics and investigate the inverse spectral problem of recovering the coefficients of the differential equation from the so-called Weyl vector which is a generalization of the Weyl function (m-function) for the classical Sturm-Liouville operator. For this inverse problem we prove the uniqueness theorem and obtain a procedure for constructing the solution by the method of spectral mappings. 相似文献
920.
Summary. For analytic functions the remainder term of quadrature rules can be represented as a contour integral with a complex kernel
function. From this representation different remainder term estimates involving the kernel are obtained. It is studied in
detail how polynomial biorthogonal systems can be applied to derive sharp bounds for the kernel function. It is shown that
these bounds are practical to use and can easily be computed. Finally, various numerical examples are presented.
Received March 11, 1998 / Revised version January 22, 1999/ Published online November 17, 1999 相似文献